High-speed networks are continually evolving. The evolution includes a continuing advancement in the operational speed of the networks. The network implementation of choice that has emerged is Ethernet networks physically connected over unshielded twisted pair wiring. Ethernet in its 10BASE-T form is one of the most prevalent high speed LANs (local area network) for providing connectivity between personal computers, workstations and servers.
High-speed LAN technologies include 100BASE-T (Fast Ethernet) and 1000BASE-T (Gigabit Ethernet). Fast Ethernet technology has provided a smooth evolution from 10 Megabits per second (Mbps) performance of 10BASE-T to the 100 Mbps performance of 100BASE-T. Gigabit Ethernet provides 1 Gigabit per second (Gbps) bandwidth with essentially the simplicity of Ethernet. There is a desire to increase operating performance of Ethernet to even greater data rates.
FIG. 1 shows a block diagram of an Ethernet transceiver pair communicating over a bi-directional transmission channel, according to the prior art. The transceiver pair includes a first transceiver 100 and a second transceiver 105. The first transceiver 100 includes a transmitter section 110 that transmits digital data over a transmission channel 135 to a receiver section 160 of the second transceiver. The first transceiver also includes a receiver section 120 that receives data from the transmitter section of the second transceiver 105. The transmission channel can be four twisted pairs of copper wire.
An implementation of high speed Ethernet networks includes simultaneous, full bandwidth transmission, in both directions (termed full duplex), within a selected frequency band. When configured to transmit in full duplex mode, Ethernet line cards are generally required to have transmitter and receiver sections of an Ethernet transceiver connected to each other in a parallel configuration to allow both the transmitter and receiver sections to be connected to the same twisted wiring pair for each of four pairs.
10GBase-T Ethernet systems require a level of signal to noise/interference performance to properly operate. If the signal to noise/interference is below the required level, typically, a 1000Base-T system is automatically switched to by default. The 1000Base-T system requires a completely different set of processing circuits for transmission of data. This results in the use of additional transmission circuitry, and a much lower data rate than the transmission channel can provide.
FIG. 2 shows a prior art Ethernet configuration that includes 10GBase-T, 1000Base-T and 100Base-T circuitry. Essentially, a single transceiver supports all of the different Ethernet protocols. This includes all transmitter and receiver processing circuitry for all the different protocols. This configuration is inefficient for several reasons. First of all, this configuration requires all the processing circuitry of all the different protocols. That is, there is minimal overlap in the use of the circuitry required for each of the different protocols. Additionally, the protocol that is used is selected based upon the level of transmission signal quality. That is, if a signal quality is below the 10GBase-T protocol, then the 1000Base-T protocol is used. The protocol is automatically switched to a 1000Base-T protocol which provides a data transmission rate ten times as slow. In fact, the transmission channel may be able to support a data transmission rate that is substantially greater. The result is slower data transmission than the transmission channel can support.
It is desirable to optimize the data transmission rate of high-speed Ethernet network connections. It is additionally desirable to minimize the electronic circuitry required to support the data transmission.